]> www.pilppa.org Git - linux-2.6-omap-h63xx.git/blobdiff - fs/ext4/namei.c
ext4: New rec_len encoding for very large blocksizes
[linux-2.6-omap-h63xx.git] / fs / ext4 / namei.c
index 04824958cba511259f0889eac2649be22a88ef45..a5ba1a858094409b5d91fd36f3e6a6ad1e5dd290 100644 (file)
@@ -165,7 +165,7 @@ static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
                       struct dx_hash_info *hinfo, struct dx_map_entry map[]);
 static void dx_sort_map(struct dx_map_entry *map, unsigned count);
 static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
-               struct dx_map_entry *offsets, int count);
+               struct dx_map_entry *offsets, int count, unsigned blocksize);
 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
 static void dx_insert_block(struct dx_frame *frame,
                                        u32 hash, ext4_lblk_t block);
@@ -180,14 +180,38 @@ static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
                             struct inode *inode);
 
+unsigned int ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize)
+{
+       unsigned len = le16_to_cpu(dlen);
+
+       if (len == EXT4_MAX_REC_LEN || len == 0)
+               return blocksize;
+       return (len & 65532) | ((len & 3) << 16);
+}
+  
+__le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize)
+{
+       if ((len > blocksize) || (blocksize > (1 << 18)) || (len & 3))
+               BUG();
+       if (len < 65536)
+               return cpu_to_le16(len);
+       if (len == blocksize) {
+               if (blocksize == 65536)
+                       return cpu_to_le16(EXT4_MAX_REC_LEN);
+               else 
+                       return cpu_to_le16(0);
+       }
+       return cpu_to_le16((len & 65532) | ((len >> 16) & 3));
+}
+
 /*
  * p is at least 6 bytes before the end of page
  */
 static inline struct ext4_dir_entry_2 *
-ext4_next_entry(struct ext4_dir_entry_2 *p)
+ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
 {
        return (struct ext4_dir_entry_2 *)((char *)p +
-               ext4_rec_len_from_disk(p->rec_len));
+               ext4_rec_len_from_disk(p->rec_len, blocksize));
 }
 
 /*
@@ -294,7 +318,7 @@ static struct stats dx_show_leaf(struct dx_hash_info *hinfo, struct ext4_dir_ent
                        space += EXT4_DIR_REC_LEN(de->name_len);
                        names++;
                }
-               de = ext4_next_entry(de);
+               de = ext4_next_entry(de, size);
        }
        printk("(%i)\n", names);
        return (struct stats) { names, space, 1 };
@@ -585,7 +609,7 @@ static int htree_dirblock_to_tree(struct file *dir_file,
        top = (struct ext4_dir_entry_2 *) ((char *) de +
                                           dir->i_sb->s_blocksize -
                                           EXT4_DIR_REC_LEN(0));
-       for (; de < top; de = ext4_next_entry(de)) {
+       for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
                if (!ext4_check_dir_entry("htree_dirblock_to_tree", dir, de, bh,
                                        (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
                                                +((char *)de - bh->b_data))) {
@@ -663,7 +687,7 @@ int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
        }
        if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
                de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
-               de = ext4_next_entry(de);
+               de = ext4_next_entry(de, dir->i_sb->s_blocksize);
                if ((err = ext4_htree_store_dirent(dir_file, 2, 0, de)) != 0)
                        goto errout;
                count++;
@@ -732,7 +756,7 @@ static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
                        cond_resched();
                }
                /* XXX: do we need to check rec_len == 0 case? -Chris */
-               de = ext4_next_entry(de);
+               de = ext4_next_entry(de, blocksize);
        }
        return count;
 }
@@ -832,7 +856,8 @@ static inline int search_dirblock(struct buffer_head *bh,
                        return 1;
                }
                /* prevent looping on a bad block */
-               de_len = ext4_rec_len_from_disk(de->rec_len);
+               de_len = ext4_rec_len_from_disk(de->rec_len,
+                                               dir->i_sb->s_blocksize);
                if (de_len <= 0)
                        return -1;
                offset += de_len;
@@ -996,7 +1021,7 @@ static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct q
                de = (struct ext4_dir_entry_2 *) bh->b_data;
                top = (struct ext4_dir_entry_2 *) ((char *) de + sb->s_blocksize -
                                       EXT4_DIR_REC_LEN(0));
-               for (; de < top; de = ext4_next_entry(de)) {
+               for (; de < top; de = ext4_next_entry(de, sb->s_blocksize)) {
                        int off = (block << EXT4_BLOCK_SIZE_BITS(sb))
                                  + ((char *) de - bh->b_data);
 
@@ -1109,7 +1134,8 @@ static inline void ext4_set_de_type(struct super_block *sb,
  * Returns pointer to last entry moved.
  */
 static struct ext4_dir_entry_2 *
-dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count)
+dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
+               unsigned blocksize)
 {
        unsigned rec_len = 0;
 
@@ -1118,7 +1144,7 @@ dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count)
                rec_len = EXT4_DIR_REC_LEN(de->name_len);
                memcpy (to, de, rec_len);
                ((struct ext4_dir_entry_2 *) to)->rec_len =
-                               ext4_rec_len_to_disk(rec_len);
+                               ext4_rec_len_to_disk(rec_len, blocksize);
                de->inode = 0;
                map++;
                to += rec_len;
@@ -1137,12 +1163,12 @@ static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
 
        prev = to = de;
        while ((char*)de < base + blocksize) {
-               next = ext4_next_entry(de);
+               next = ext4_next_entry(de, blocksize);
                if (de->inode && de->name_len) {
                        rec_len = EXT4_DIR_REC_LEN(de->name_len);
                        if (de > to)
                                memmove(to, de, rec_len);
-                       to->rec_len = ext4_rec_len_to_disk(rec_len);
+                       to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
                        prev = to;
                        to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
                }
@@ -1215,10 +1241,12 @@ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
                                        hash2, split, count-split));
 
        /* Fancy dance to stay within two buffers */
-       de2 = dx_move_dirents(data1, data2, map + split, count - split);
+       de2 = dx_move_dirents(data1, data2, map + split, count - split, blocksize);
        de = dx_pack_dirents(data1, blocksize);
-       de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de);
-       de2->rec_len = ext4_rec_len_to_disk(data2 + blocksize - (char *) de2);
+       de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de,
+                                          blocksize);
+       de2->rec_len = ext4_rec_len_to_disk(data2 + blocksize - (char *) de2,
+                                           blocksize);
        dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1));
        dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1));
 
@@ -1268,6 +1296,7 @@ static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
        const char      *name = dentry->d_name.name;
        int             namelen = dentry->d_name.len;
        unsigned int    offset = 0;
+       unsigned int    blocksize = dir->i_sb->s_blocksize;
        unsigned short  reclen;
        int             nlen, rlen, err;
        char            *top;
@@ -1275,7 +1304,7 @@ static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
        reclen = EXT4_DIR_REC_LEN(namelen);
        if (!de) {
                de = (struct ext4_dir_entry_2 *)bh->b_data;
-               top = bh->b_data + dir->i_sb->s_blocksize - reclen;
+               top = bh->b_data + blocksize - reclen;
                while ((char *) de <= top) {
                        if (!ext4_check_dir_entry("ext4_add_entry", dir, de,
                                                  bh, offset)) {
@@ -1287,7 +1316,7 @@ static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
                                return -EEXIST;
                        }
                        nlen = EXT4_DIR_REC_LEN(de->name_len);
-                       rlen = ext4_rec_len_from_disk(de->rec_len);
+                       rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
                        if ((de->inode? rlen - nlen: rlen) >= reclen)
                                break;
                        de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
@@ -1306,11 +1335,11 @@ static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
 
        /* By now the buffer is marked for journaling */
        nlen = EXT4_DIR_REC_LEN(de->name_len);
-       rlen = ext4_rec_len_from_disk(de->rec_len);
+       rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
        if (de->inode) {
                struct ext4_dir_entry_2 *de1 = (struct ext4_dir_entry_2 *)((char *)de + nlen);
-               de1->rec_len = ext4_rec_len_to_disk(rlen - nlen);
-               de->rec_len = ext4_rec_len_to_disk(nlen);
+               de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, blocksize);
+               de->rec_len = ext4_rec_len_to_disk(nlen, blocksize);
                de = de1;
        }
        de->file_type = EXT4_FT_UNKNOWN;
@@ -1380,7 +1409,7 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
        /* The 0th block becomes the root, move the dirents out */
        fde = &root->dotdot;
        de = (struct ext4_dir_entry_2 *)((char *)fde +
-               ext4_rec_len_from_disk(fde->rec_len));
+               ext4_rec_len_from_disk(fde->rec_len, blocksize));
        if ((char *) de >= (((char *) root) + blocksize)) {
                ext4_error(dir->i_sb, __func__,
                           "invalid rec_len for '..' in inode %lu",
@@ -1402,12 +1431,14 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
        memcpy (data1, de, len);
        de = (struct ext4_dir_entry_2 *) data1;
        top = data1 + len;
-       while ((char *)(de2 = ext4_next_entry(de)) < top)
+       while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
                de = de2;
-       de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de);
+       de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de,
+                                          blocksize);
        /* Initialize the root; the dot dirents already exist */
        de = (struct ext4_dir_entry_2 *) (&root->dotdot);
-       de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2));
+       de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
+                                          blocksize);
        memset (&root->info, 0, sizeof(root->info));
        root->info.info_length = sizeof(root->info);
        root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
@@ -1488,7 +1519,7 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
                return retval;
        de = (struct ext4_dir_entry_2 *) bh->b_data;
        de->inode = 0;
-       de->rec_len = ext4_rec_len_to_disk(blocksize);
+       de->rec_len = ext4_rec_len_to_disk(blocksize, blocksize);
        return add_dirent_to_buf(handle, dentry, inode, de, bh);
 }
 
@@ -1551,7 +1582,8 @@ static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
                        goto cleanup;
                node2 = (struct dx_node *)(bh2->b_data);
                entries2 = node2->entries;
-               node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize);
+               node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
+                                                          sb->s_blocksize);
                node2->fake.inode = 0;
                BUFFER_TRACE(frame->bh, "get_write_access");
                err = ext4_journal_get_write_access(handle, frame->bh);
@@ -1639,6 +1671,7 @@ static int ext4_delete_entry(handle_t *handle,
                             struct buffer_head *bh)
 {
        struct ext4_dir_entry_2 *de, *pde;
+       unsigned int blocksize = dir->i_sb->s_blocksize;
        int i;
 
        i = 0;
@@ -1652,8 +1685,11 @@ static int ext4_delete_entry(handle_t *handle,
                        ext4_journal_get_write_access(handle, bh);
                        if (pde)
                                pde->rec_len = ext4_rec_len_to_disk(
-                                       ext4_rec_len_from_disk(pde->rec_len) +
-                                       ext4_rec_len_from_disk(de->rec_len));
+                                       ext4_rec_len_from_disk(pde->rec_len,
+                                                              blocksize) +
+                                       ext4_rec_len_from_disk(de->rec_len,
+                                                              blocksize),
+                                       blocksize);
                        else
                                de->inode = 0;
                        dir->i_version++;
@@ -1661,9 +1697,9 @@ static int ext4_delete_entry(handle_t *handle,
                        ext4_handle_dirty_metadata(handle, dir, bh);
                        return 0;
                }
-               i += ext4_rec_len_from_disk(de->rec_len);
+               i += ext4_rec_len_from_disk(de->rec_len, blocksize);
                pde = de;
-               de = ext4_next_entry(de);
+               de = ext4_next_entry(de, blocksize);
        }
        return -ENOENT;
 }
@@ -1793,6 +1829,7 @@ static int ext4_mkdir(struct inode *dir, struct dentry *dentry, int mode)
        struct inode *inode;
        struct buffer_head *dir_block;
        struct ext4_dir_entry_2 *de;
+       unsigned int blocksize = dir->i_sb->s_blocksize;
        int err, retries = 0;
 
        if (EXT4_DIR_LINK_MAX(dir))
@@ -1824,13 +1861,14 @@ retry:
        de = (struct ext4_dir_entry_2 *) dir_block->b_data;
        de->inode = cpu_to_le32(inode->i_ino);
        de->name_len = 1;
-       de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len));
+       de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
+                                          blocksize);
        strcpy(de->name, ".");
        ext4_set_de_type(dir->i_sb, de, S_IFDIR);
-       de = ext4_next_entry(de);
+       de = ext4_next_entry(de, blocksize);
        de->inode = cpu_to_le32(dir->i_ino);
-       de->rec_len = ext4_rec_len_to_disk(inode->i_sb->s_blocksize -
-                                               EXT4_DIR_REC_LEN(1));
+       de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(1),
+                                          blocksize);
        de->name_len = 2;
        strcpy(de->name, "..");
        ext4_set_de_type(dir->i_sb, de, S_IFDIR);
@@ -1885,7 +1923,7 @@ static int empty_dir(struct inode *inode)
                return 1;
        }
        de = (struct ext4_dir_entry_2 *) bh->b_data;
-       de1 = ext4_next_entry(de);
+       de1 = ext4_next_entry(de, sb->s_blocksize);
        if (le32_to_cpu(de->inode) != inode->i_ino ||
                        !le32_to_cpu(de1->inode) ||
                        strcmp(".", de->name) ||
@@ -1896,9 +1934,9 @@ static int empty_dir(struct inode *inode)
                brelse(bh);
                return 1;
        }
-       offset = ext4_rec_len_from_disk(de->rec_len) +
-                ext4_rec_len_from_disk(de1->rec_len);
-       de = ext4_next_entry(de1);
+       offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
+                ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
+       de = ext4_next_entry(de1, sb->s_blocksize);
        while (offset < inode->i_size) {
                if (!bh ||
                        (void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
@@ -1927,8 +1965,8 @@ static int empty_dir(struct inode *inode)
                        brelse(bh);
                        return 0;
                }
-               offset += ext4_rec_len_from_disk(de->rec_len);
-               de = ext4_next_entry(de);
+               offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
+               de = ext4_next_entry(de, sb->s_blocksize);
        }
        brelse(bh);
        return 1;
@@ -2297,8 +2335,8 @@ retry:
        return err;
 }
 
-#define PARENT_INO(buffer) \
-       (ext4_next_entry((struct ext4_dir_entry_2 *)(buffer))->inode)
+#define PARENT_INO(buffer, size) \
+       (ext4_next_entry((struct ext4_dir_entry_2 *)(buffer), size)->inode)
 
 /*
  * Anybody can rename anything with this: the permission checks are left to the
@@ -2358,7 +2396,8 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
                dir_bh = ext4_bread(handle, old_inode, 0, 0, &retval);
                if (!dir_bh)
                        goto end_rename;
-               if (le32_to_cpu(PARENT_INO(dir_bh->b_data)) != old_dir->i_ino)
+               if (le32_to_cpu(PARENT_INO(dir_bh->b_data,
+                               old_dir->i_sb->s_blocksize)) != old_dir->i_ino)
                        goto end_rename;
                retval = -EMLINK;
                if (!new_inode && new_dir != old_dir &&
@@ -2430,7 +2469,8 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
        if (dir_bh) {
                BUFFER_TRACE(dir_bh, "get_write_access");
                ext4_journal_get_write_access(handle, dir_bh);
-               PARENT_INO(dir_bh->b_data) = cpu_to_le32(new_dir->i_ino);
+               PARENT_INO(dir_bh->b_data, new_dir->i_sb->s_blocksize) =
+                                               cpu_to_le32(new_dir->i_ino);
                BUFFER_TRACE(dir_bh, "call ext4_handle_dirty_metadata");
                ext4_handle_dirty_metadata(handle, old_dir, dir_bh);
                ext4_dec_count(handle, old_dir);